Like most corvids, White-throated Magpie-jays have a relatively catholic diet, consisting of a range of vegetable and animal sources, the proportions of which vary seasonally (Langen 1996c). During the dry season in Costa Rica, the primary food sources are small fruits, in particular those of ant-acacias (Acacia cornigera, Acacia collinsii). Wet season diets are dominated by caterpillars, though fruits are still consumed (Leck 1969, Langen 1996b, c; Langen and Vehrencamp 1998). Like many other jays, White-throated Mapgie-jays also take a range of large arthropods, including stick insects, cockroaches, and cicadas, and small vertebrates, including geckos, nestling birds, and eggs. Wasp larvae and eggs are also preferred prey. Additionally, White-throated Magpie-jays are occasionally observed eating nectar (Spofford & Fisk 1977; JME pers. obs). A brief investigation of feces found that seeds of Acacia cornigera were passed whole, suggesting that these birds are not at all seed predators (JME, pers. obs). Magpie-jays have also been observed landing on the backs of white-tailed deer (Odocoileus virginianus) and picking off invertebrates, presumably ticks (JME and T. Langen, pers. obs.).